This study is intended to evaluate the ability of a new non-invasive optical technique known as TOFA and compare this system with others, the DOTS and ITSS oximeters, in monitoring oxygenation and blood flow in infants who may have oxygenation and functional inadequacies arising from structural diseases of the brain as well as in control infants. We will also examine the brain function in healthy adults, brain function as defined by motor cortex response. The TOFA device which was funded by the GCRC can spacially assess changes in the distribution of blood oxygenation and blood flow.